4.89. A Ramsden ocular consists of two thin plano-convex lenses, each of focal length f1, separated by 2f1/3, with the c
Posted: Mon Jul 18, 2022 6:03 am
4.89. A Ramsdenocular consists of two thin plano-convex lenses, each of focallength f1, separated by 2f1/3, with the curved surfaces facing eachother. Locate the object plane (Sigma0) in front of the Ocular suchthat light diverging from any point on sigma0 emerges as acollimated beam. In practice, an objective lens would form a realimage on sigma0 (where there might also be a pair Of cross hairs),which is then converted into parallel light by the ocular so thatthe eye can view it in a relaxed (unaccommodated) fashion.
Ans. Sigma0 must be a distance away equal to the effective focal length f= 3f1/4.
Ans. Sigma0 must be a distance away equal to the effective focal length f= 3f1/4.